MONTREAL - Last fall, as archeologist Yves Chrétien was supervising a team digging at the site of a future hockey rink northeast of Montreal, a mini excavator unearthed pieces of cut stone.

MONTREAL — Last fall, as archeologist Yves Chrétien was supervising a team digging at the site of a future hockey rink northeast of Montreal, a mini excavator unearthed pieces of cut stone. Formed ...